Can you overrride the absurd 8000cm RTL_ALT limit somehow?

ArduPlane Plane 3.3
1

Ideally I am hoping there is a setting like return home 200ft above current height instead of the regular “crash airplane” setting that it defaults to.

APM only lets you set a maximum of 8000cm above launch for RTL but this is problematic in two ways:

  1. Sometimes RTL engages because the dummy flying the plane flies behind a hill and it would be better if the plane to flew back up and over the hill instead of straight into the side of it.
  2. If I fly uphill more than 400ft and RTL engages APM just plants the airplane into the ground instead of flying above the ground.

I am still waiting for the technology to come out will allow me to attach a drill to my plane and fly seamlessly through the ground like they do in the cartoons but until then I’m stuck having to fly over the ground

2

Are you saying that’s a new restriction in 3.3.0? (I’m still using 3.2.3).
What is your ALT_HOLD_RTL set to?
Do you have terrain following enabled?

In 3.2.3 I’m able to use 20000 for ALT_HOLD_RTL just fine and since I fly in a mountainous area thousands of feet above my launch point, I know for sure that the terrain following works well to stay above the hills as needed. I’ve tested it many times.

TERRAIN_ENABLE,1 TERRAIN_FOLLOW,1 TERRAIN_LOOKAHD,2000 TERRAIN_SPACING,30

3

the limit is over 21km, as it is a signed 32 bit number.
Why do you think it is 80m?

4

btw, I assume you have seen this:
plane.ardupilot.com/wiki/common- … following/
terrain following for RTL is rather useful

5

because that is the max limit allowed on APM
static.rcgroups.net/forums/attac … 52100a.jpg

I haven’t tried terrain following yet. Does it work if you travel all over the place or can you only download one area’s terrain map?

6

those are parameters for copter, not plane
do you have plane firmware loaded? If you do, then it may be a MissionPlanner error

7

The terrain data is relatively small even at 30m sampling, so you can store a vast area on the microSD card in the pixhawk. You need to define a mission which enters a grid square for that one to be downloaded. Each square is several KM on a side and many will fit in the uSD.

8

Maybe that’s the problem.
I installed an APM into a copter back in January and now I am attempting to configure a plane. I downloaded Arduplane but maybe it didn’t override Arducopter like I thought it did. I will do a complete uninstall/reinstall and see if that fixes things.